More U.S. cities dimming lights with dark-sky legislation

About 300 counties, cities and towns have undertaken dark-sky legislation – laws requiring such measures as shielding outdoor lighting to reduce light pollution – across the country.

About 300 counties, cities and towns have undertaken dark-sky legislation – laws requiring such measures as shielding outdoor lighting to reduce light pollution – across the country.

More than 50 state bills have been introduced in the past two years. Seven were enacted. Eighteen states – Arizona, Arkansas, California, Colorado, Connecticut, Hawaii, Maine, Minnesota, Missouri, New Hampshire, New Mexico, New York, Oklahoma, Rhode Island, Texas, Vermont, Virginia and Wyoming – have adopted dark-sky legislation in recent years, according to USA Today.

The city of Davis is part of this trend. Davis’ Light Ordinance was proposed by then-mayor Julie Partansky and enacted in 1998 – Ordinance 1966 was established to minimize light pollution and allow people to see the night sky.

According to Michael Siminovitch, director of the California Lighting Technology Center, the UC Davis campus has mostly bi-level lighting, meaning lights are dimmed to 50 percent when buildings are empty. Siminovitch said dimming is becoming a trend with colleges and universities.

Pete Strasser, technology director for the International Dark-Sky Association and UC Davis alumni, said the majority of lighting is still older, high intensity discharge lamps. He agreed there is a trend toward more light dimming mostly due to new technology such as light-emitting diodes (LEDs) and induction lighting, which use less energy than standard lighting and will dim when areas are unoccupied.

UC Davis is among the universities that joined the LED University program in April 2008. The program is designed to accelerate the adoption of LED lighting to significantly reduce the amount of electricity used to power lighting on campuses. Initial participants North Carolina State University, Marquette University, UC Santa Barbara, University of Arkansas and Tianjin Polytechnic University in China began evaluating and deploying LED lighting in offices, dormitories, parking garages, walkway lighting and streets throughout their campuses.

UC Davis’ Mondavi Center parking lot had LED lighting installed in 2009. Switching to LED and adding bi-level activity-sensing lights saves 50 percent of energy when the lights are at full power and 80 percent when at half power. Based on nighttime bi-level operation, the Mondavi Center’s south entry parking structure does not need re-lamping and is virtually maintenance free for 20 to 25 years, according to the installers, BetaLED.

Strasser said the new lighting has a higher initial cost and scientists are currently working on other technology, such as creating dimmers for older lamps.

“The new lighting allows for energy and money savings,” Strasser said. “We do need to do more research on the longevity of the new lighting and observe the effects of short wave length emissions on the nocturnal environment, something that has never been apart of the nocturnal habitat.”

Illuminating Engineering Society’s magazine editor Paul Tarricone said the issue of restoring the night sky has been being discussed for at least 10 years.

“This is definitely something to look out for as a trend. Cities have been enacting regulations,” Tarricone said. “The one negative is that not having enough light for security in parking lots and crosswalks is a huge safety issue. We want to respect the night sky, but at the same time provide enough light for the task at hand.”

ANGELA SWARTZ can be reached city@theaggie.org.